If you've lost access to Dashboard tabs, this may be due to temporary browser cache issues.
To fix the cache issue:
In your browser, open Developer Tools by pressing _F12 _on your keyboard or selecting it from the browser menu.
Go to the Application tab and select Storage. The tab name may vary depending on your browser_._
Select Clear site data.
Reload the page.
Alternatively, try the following:
Sign out from the Dashboard and sign in again
Open a new window in incognito mode and sign in to the Dashboard
Use a different browser
Restart the computer